Technology Brief

Why sodium-ion beats lithium where it actually matters.

A short version of the long argument: cold weather, supply chain, fire safety, and price. We lose on energy density. We win on everything that wakes a customer up at 4 AM.

The Comparison

Sodium-ion vs. lithium iron phosphate vs. lead-acid AGM.

For powersports and starter applications, lithium isn’t the obvious winner you’ve been told it is. Here’s what the data actually shows.

Metric
Sodium-ion (Power11)
LFP (lithium)
Lead-acid AGM
Capacity at -20°C
>90%
~50%
~30%
Cold cranking (CCA)
High
Moderate
Moderate
Thermal runaway threshold
~292°C
~200°C
N/A (off-gases)
Critical mineral content
None
Lithium
Lead
Cycle life (80% DoD)
3,000+
3,000+
~500
Self-discharge / month
~2%
~3%
~10–15%
Energy density (Wh/kg)
~140
~160
~35
Tariff / supply risk
Low
High (China)
Low

Why Cold Matters

The cold-weather curve is the whole game.

Powersports vehicles sit outside, often unheated, often un-trickle-charged, often through Wyoming, Minnesota, Maine, and Montana winters. The chemistry that survives that wins the customer for life.

-20°C
The temperature at which lithium starts losing measurable capacity. Sodium-ion holds >90% past this threshold.
Threshold

2-3×
Cold-discharge current vs. comparable lithium and AGM packs at the same temperature.
Cold cranking

Cycle life vs. AGM under the same use pattern. Five winters before a customer thinks “I need a new battery.”
Longevity

0
Lithium, cobalt, or nickel. No conflict minerals. No fire-marshal calls.
Critical minerals

The Chemistry

Sodium ions move fast. Even when it’s cold.

Sodium has a larger ionic radius than lithium, which means lower energy density on paper — but it also means looser solvation shells in the electrolyte, which means the ions stay mobile at temperatures where lithium starts to seize. The same property that makes sodium-ion “less dense” makes it survive winter.

Cathode: Prussian-blue-analog or layered oxide. Anode: hard carbon. Electrolyte: NaPF₆ in carbonate solvents. Same general manufacturing process as lithium-ion — different feedstock, different supply chain, different cold-weather curve.

No Lithium

Sodium is the sixth most abundant element on Earth. The supply curve is flat for the next century.

No Cobalt or Nickel

No conflict-mineral risk, no DRC supply chain, no ESG audit anxiety.

Domestic Feedstock

Sodium carbonate is mined in Wyoming. Hard carbon precursors are agricultural waste streams.

Deeper Reading

Want the technical brief?

Spec sheets, third-party test data, and the Phase 1 cell-level performance summary. Available to dealers, investors, and engineering partners under NDA.